There are several applications where hydraulic connectors are utilized for inter-connecting hydraulically controlled equipments with systems of pressurized hydraulic fluid comprising control means such as valves for directing the pressurized fluid to different parts of the equipment and/or different functions of the equipment.
In many applications it is advantageous if the hydraulic connections are of a so called multi coupling type, with which it is possible to connect and disconnect the hydraulically controlled equipment from the source in one single operation. One such application is work vehicles for e.g. agricultural use, i.e. tractors, which utilize a number of different equipment such as digging aggregates, lifting aggregates, ploughs and the like. These are hydraulically operated via conduits and valve systems connected to a source of pressurized fluid, such as hydraulic pumps, which are driven by the engine of the work vehicle. Often, such an equipment is disconnected from the tractor when it is not to be used for a while, such that it may be replaced by another hydraulically controlled equipment.
A few systems for facilitating the operation of coupling the hydraulically controlled equipment to the work vehicle have been developed. One is disclosed in EP 0 522 493, in which hydraulic conduits are attached to carrier plates, one carrier plate being attached in a fixed position on e.g. a work vehicle, and the other carrier plate being arranged to the attachable equipment. The carrier plates are arranged with leakage proof quick-acting couplings. For connecting the couplings, a handle is pivotally arranged on the fixedly attached carrier plate, which co-operates with a couple of clamping pins arranged on the other carrier plate.
An obvious advantage of a multi coupling, such as the one described in EP 0 522 493 is of course that the exchange of equipments on the work vehicle may be easily and quickly performed. A drawback is however that once the work vehicle is supplied with such a carrier plate all equipment that are intended for use on that work vehicle, i.e. digging aggregates, lifting aggregates, ploughs etc., needs to be furnished with a corresponding carrier plate. This may infer heavy investment costs that are in some cases difficult to recover. Some of the equipments are only used once or twice a year, wherein such an investment is not worth wile.
Another drawback with the solution presented in EP 0 522 493 is that when the carrier plates are disconnected from each other, the couplings are not protected and are thus exposed to harming elements of the environment, such as dirt, debris, snow, rain and ice. This could adversely affect the hydraulic system, leading to malfunction and breakdown with rather costly repairs as a result.